The present invention relates to a plug-in connector which is suitable for use in a fluid medium. In the following, reference will be made, by way of non-limitative example only, to an electric connector whose contact elements are protected against the surrounding medium, so that electrical connections can be established and interrupted even if the connector is immersed in a liquid medium which may be electrically conductive.
Different types of connectors are already known which are specially designed so that the plug and socket constituting the connector can be assembled when submerged in a liquid.
One of these connectors, which is described in French Pat. No. 1 490 351, uses a fluidtight diaphragm which protects the electrical contacts of the socket. When the electrical connection is established, the plug pierces the diaphragm and thus destroys it. Consequently, only one operation of plug and socket connection can be effected under water. Such a connector is therefore unsuitable when electrical connection must be established and interrupted several times in a liquid medium.
In order to obviate this drawback other connectors have been built in which the electrical contacts of the socket are protected by a suitable liquid. A retractable piston holds this liquid in the socket and expels this liquid into a special space provided therefor, as the plug is inserted into the socket. U.S. Pat. No. 3,508,188, U.S. Pat. No. 3,845,450, U.S. Pat. No. 4,039,242 and U.S. Pat. No. 4,172,770 illustrate two embodiments of this type of connector which can be operated several times while remaining under water.
The drawbacks of these last-mentioned devices result from the fact that, every time the connector is operated, a certain amount of the protecting liquid is discharged from the socket. Moreover, when solid particles are in suspension in the liquid where the connector is immersed, experience shows that a larger or lesser amount of these particles penetrates into the socket and causes a more or less rapid deterioration of the connector.
The present invention provides a new electrical connector which does not suffer from the above-indicated drawbacks.